FLORA OF THE YELLOWSTONE.
The most conspicuous feature of the Park flora is the wide extent of
forest growth which covers some eighty-four per cent of its area. This
is the more noticeable because the surrounding country below the
mountains is practically treeless. The Park forests consist almost
exclusively of pine and fir. The trees are generally tall and slender
and of little use for lumber. They are usually unattractive in
appearance, although in some places among the mountains the spruce and
fir attain a size, form and hue of foliage that are exceedingly
beautiful.
Among the several species may be noted the following:
Black pine (_Pinus Murrayana_) so called from the dark hue of its
foliage when seen in dense bodies.
Red fir (_Pseudotsuga Douglasii_) the largest variety in the Park,
sometimes attaining a diameter of five feet.
Balsam (_Abies subalpina_). It flourishes near the snow fields and is
the beauty of the forest.
Spruce (_Pinus Engelmanni_). Like the preceding it flourishes at high
altitudes. It is tall and slender, and is good for lumber.
Red cedar (_Juniperus virginiana_) is found to a limited extent.
Poplar or aspen (_Populus tremuloides_) flourishes among the sheltered
foot-hills.
Dwarf maple is occasionally found.
Willow thickets abound in great abundance.
Of these varieties the first is found more abundantly than all the
others combined. In many places it has fallen down and strews the
country to such an extent as to be absolutely impassable on horseback.
There is very little timber of marketable value, and at first thought
it would seem that nature has here lavished her energies in a most
wasteful manner.
But the great value of these forest growths, is their agency in the
conservation of a water supply for the surrounding country. A glance
at the map will show that the Park is in the midst of a vast arid
region extending far into the surrounding states. The reclamation of
these desert wastes, and their conversion into productive lands, can
be accomplished by irrigation alone, and for this purpose the abundant
streams which descend from the mountains are the indispensable water
supply.
From the summit of the Grand Teton, the range of vision covers
probably the most remarkable group of river sources upon the earth. To
the north rises the Missouri which flows three thousand miles through
Montana, the Dakotas, Iowa, Nebraska, Kansas and Missouri. To the east
rises the Yellowstone, which, after leaving the Park, flows four
hundred miles through southern and eastern Montana until it unites
with the Missouri. From the eastern foot-hills of the Absaroka and
Shoshone Ranges flow the Wind and Big Horn Rivers through the
extensive valleys of the same names in Wyoming and Montana.
Southwardly, across the Wind River Range rises the Platte which flows
eastward eight hundred miles through Wyoming and Nebraska. From the
west flank of these mountains issue the tributaries of the Green River
(afterward the Colorado) which flows through Wyoming, Utah and Arizona
into the Gulf of California. Finally, interlaced with the sources of
the Yellowstone, and the Missouri, are those of the Snake River which
flows through Wyoming, Idaho and Washington into the Columbia, and
thus reaches the Pacific.
Not only do these streams rise in this limited area; they derive from
it most of their waters. In the arid lowlands they receive but slight
accessions, and often actually shrink under evaporation. It is
therefore from a relatively small tract of country that the future
water supply must come for portions of ten states in the great arid
belt of the west.
The conditions which nature has established around this remarkable
fountain-head are admirably adapted for the creation and maintenance
of an unlimited water supply. Over an area of more than 5,000 square
miles there prevails an average altitude of perhaps 7,500 feet;
sufficient to insure enormous annual snowfalls, but not so great as to
prevent their complete melting in summer. But, that they may not melt
too rapidly, the whole region is covered with a thick forest growth
cutting off the intense rays of the summer sun, and covering the
ground with a vegetable mold through which the surface waters filter
but slowly. It is a conservative estimate, based upon observations in
connection with road work in the Park, that these forests prolong the
melting of the snows from four to six weeks. This condition greatly
lessens the liability to sudden floods, and maintains a generous
supply of water far into the summer.
It has been estimated[AW] that from the Park alone, at low water,
there flows per second 4,000 cubic feet of water. If the time ever
comes when this supply is so far used as to threaten exhaustion, there
will be found in the basin of Yellowstone Lake the most perfect
facilities in the world for the construction of an artificial
reservoir of almost limitless capacity at a comparatively
insignificant cost. A dam could be thrown across the gorge at the
first rapids in the Yellowstone below the Lake, and without injuring
the natural condition of that region, could easily be made to
quadruple the present capacity of the Lake.
[AW] By Dr. William Hallock, United States Geological Survey.
The Park with its contiguous area thus presents magnificent
possibilities in the development of the surrounding
country--possibilities of which its founders little dreamed, but which
they unconsciously foreshadowed when they declared that this region
should be forever set apart for the "benefit" as well as for the
"enjoyment" of the people.
Besides its wealth of trees, the Park produces other interesting
flora. Interspersed among the forests and ornamenting the open glades
are flowers and shrubs in endless profusion. We quote from the
description of one of the early visitors:
"The choke-cherry, the goose-berry, the buffalo-berry, and black and
red currants, are found along the streams and in moist places of the
middle and lower altitudes. The meadows and hill-sides are spangled
with bright-colored flowers, among which may be noted the
bee-larkspur, the columbine, the harebell, the lupine, the evening
primrose, the aster, the painted cup, the gentian, and various kinds
of euphorbia. It is not uncommon to find daises, buttercups,
forget-me-nots, white-ground phlox, and other field flowers
flourishing in profusion near the melting snow banks during the month
of August. Scarcely a night throughout the year passes without frost,
even though the temperature by day is over 80 F., so that all forms of
vegetation in the Park grow and bloom under somewhat unusual
conditions. Indeed, when ice forms in the water-pails of camping
parties during the night, as often happens, and the petals of the
flowers become crisp with frost; even then the blooms are not harmed,
but thaw out bright and fresh when the hot sun touches them."
The flowers form a most attractive feature of the Park, and give an
interesting study of the way in which altitude and temperature affect
well known varieties. It is only after a second look that one can
trace in the mountain dandelion, huckleberry, and other species a
resemblance to those of lower altitudes. The extreme shortness of the
season causes vegetation to mature quickly, and before the flush of
spring has disappeared from the leaves the palor of autumn makes its
appearance.
The mountain grasses are generally abundant in the open country and
even in many places among the forests. The writer just quoted says:
"The pasturage on the many open spaces is excellent, the mountain
meadows being covered with a mat of nutritious grasses. The
predominating variety is the bunch grass, upon which the horses of
tourists generally subsist, keeping in good condition without the need
of oats. Among other kinds, are the blue joint, fescue, and beard
grasses, as well as Alpine timothy, all of which grow luxuriantly."
The early autumns tinge the foliage of the willow parks and other
groups of shrubbery with a wealth of color not often seen elsewhere.
Even the frost on the grass upon sharp mornings seems to have a
peculiar beauty, and one may trace terrestrial rainbows in all the
perfection of those set in the sky.